(a) Field
Embodiments of the present invention relate generally to flat panel displays. More specifically, embodiments of the present invention relate to a display device provided with a touch panel.
(b) Description of the Related Art
Flat panel display devices have largely replaced cathode-ray tube display devices due to characteristics such as superior lightness, thinness, and the like. As representative examples of flat panel display devices, there are the liquid crystal display (LCD) device and the organic light emitting diode (OLED) display device. The organic light emitting diode (OLED) display device can have excellent luminance and viewing angle and does not require a back light and thus can be implemented as an ultra-thin type display, as compared with the liquid crystal display (LCD) device.
The organic electric field emissive display device can be characterized as a passive matrix type or an active matrix type according to its driving method, and the active matrix device includes a circuit using thin film transistors (TFTs).
Recently, the organic electric field emissive display device has been used with a digitizer such as a touch panel for detecting a position of a finger or a pen in a digital manner, converting it into an XY coordinate value, outputting the value, and thereby inputting letters or pictures more easily and precisely on one side of a display panel for realizing images, so that a user may watch the images displayed on the display panel and select desired information.
The touch panel can be classified by its method for sensing contact, and in particular can be characterized as a resistive type panel determining a contact position as a resistance-induced voltage gradient while a DC voltage is applied, or a capacitive type panel forming an equipotential on a conductive layer and sensing a position where a voltage is changed according to a contact.
Particularly, regarding the capacitive type, when a touch is performed without a finger or a conductor, no change of voltage caused by a contact is generated so the touch cannot be recognized, and an additional pressure sensor is required to recognize the touch depending on a position and magnitude of the pressure. This results in an increase in production cost.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.